Signaling system for electric railways.



No 849,173, PATENTED APR. 2, 1907:

. J. B. STBUBLE.

SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLICATION FILED JAN. 3, 1907.. v

3 SHEBTSSHEBT -1.

PATENTED APR. 2, 1907.

J. B. STRUBLB, SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLIOATIO N FILED JAN. 3, 1907.

3 SHEETS-SHEET 2' Wiifie WW M.

.No 84=9,173. I PATENTED APR.2,1907.

Y J.B.STRUBLE.

SIGNALING SYSTEM FOR ELECTRIC RAILWAYS,

AIPLIGATION FILED JAN. 3, 1907.

k 3 SHEETS- SHEET 3.

rinrrnn sra rns' rarer JACOB B. STRUBLE, OF

WILKINSBURG, PENSYLVANIA, ASSIGNOR TO THE UNION SWITCH AND SIGNAL COMPANY, OF SWISSVALE, PENNSYLVA- NIA, A CORPORATION OF PENNSYLVANIA.

SlGNALlNG SsS'lEiJl FOR ELEQTRlG RAELWIQYSU Specification of Letters Patent.

Patented April 2, 1937.

Application filed January 3, 1907. Serial No- 35059 To all whom it may concern: Be it known that LJAoon B. S'IRUBLE, a citizen of the United States, residing at Nilkinsbur in the county of Allegheny and 5 State 0 Pennsylvania, have invented certain new and useful. Improvements in Signaling Systems for Electric Railways, of which the following is a soecilication.

\Iy invention re ates.to signaling systems for electric railways and to the relays used in such s stems, particularly when the system is app iedjto electric railways a track-rail or the traclerails of which are used as part of the return path or conductor for the alternatr5 ing carrepulsion current.

The a ternating car-propulsion current for commercial reasons is of a low frequency, and generally the alternating signaling-cup rent is of a relatively higher frequency; and my invention has for an object a relay for the signaling systems on such railroads which will prevent or avoid the wrorn clearing of a railway-signal through the induenoe of the alternating propulsion-current on the relay.

I will describe a relay embodying my inv ention and then point out the novel features-thereoi in cldinis, as well as novel combinations existing in the si nalinc' system in which the relay is used an the electric railway to which it is applied.-

In the accompanying drawings, Figures i, 2, and 3 are diagrammatic views each representing a portion of an electric railway the track-rails of which are divided by insulation to form block-sections and form part of the return-path and a-signaling system applied thereto COIIlpIlSlBg relays embodying my invention.

The several figures illustrate different 0 erations oi the relay due to diilerent con itions.

Referring to the drawings, A designates which for the purposes of thisinventionshould he alternating and. of a low frequency, provision is rnade for conducting the propulsion current around insulation-points by means of rcactance-bonds. i i

In the drawings I have diagrammatically illustrated what is known in the art- -asthe balanced type of reactance-bond. B B B" B &c,, designate such oonds. These bonds, as is well known, comprise a core and a winding or windings, all the turns of which are in the same direction and in close inductive relation. Such a type of bond is illustrated in United-States Patent No. 838,916,

I granted December 18, 1906, to L. H. Thullen. In this type of bond the propulsionourrent is made to flow through two equal parts of the winding or two windings of the same number of turns in reverse directions, so that the propulsion-current produces no magnetizing effect on the core of the bond. As shown, the windings of two adjacent bonds are connected by a conductor 1), or there may be a plurality of such conductors. By this arrangement of track the propulsioncurrent in its return through the rails and the windings in the manner stated will not mag netize the cores oi the reaotancc-ixinds, thus leaving them free to act as impedanoes for the alternating signaling-current, which is of a higher frequency than the car-propulsion current. I have not illustrated the alternating-current generator for the car-propulsion current or the trolley or third rail, as these are well known in the art,

The signaling system applied to the railway comprises a railwa signal or signals for each block-section ant a track-circuit for each block-section to control one operation of the railway signal or signals; I have not illustrated ,anyrailway-signal, and any ol the well-known types of automatic signal maybe used. have indicated a part of the local circuit which includes the operating mechanism oi the railway-signal 7 Each track-circuit comprises a source of alternating current and a'relay. The source of alternating current for the track-circuit of each block-section is in the form of a transformer T, the secondary of which is connected with the traclcrails oi the block-section, while the primary thereof may he in multiple circuit with mains 2O 21, extending along.

rod

the track from a generator G. As hereinbefore stated, the alternating signaling-current shouldbe of a higher frequency than the alternating power-current. i

The relay of each track-circuit comprises .two coils, a movable element, here, shown as coil is continued through the second movable element. In the drawings in order that my invention may be understood I have so a rately illustrated the two coils and move le separate relays.

operates a movable e elements, making it appear that there are two in practice, however, the parts are all combined to form a single relay. C designates one coil of. the relay, and D the other coil, and each coil is located on a core constructed as set forth in United States Patent No. 823,086, granted June 12, 1906. Each core when energized through its core .ement, which I shall hereinafter designate a "vane. M M designate the cores, and C D designate the vanes. Each vane is moved when its coil is energized in the manner described in the said patent.

The vane C directly controls the local circuit and when moved in one direction on its pivots (see the arrow) closes the contacts in the local circuit for the railway-signal, and

' when it moves in a reverse direction by gravity or otherwise, which will he when its coil is deenergized, in any manner,as by a shunt,

around the coil, these contacts are opened. The vane D is mechanically connected with the vane C in any desired manner, and the connection is such that when the vane D moves on its pivot (Z in the direction of the arrow, due to its coil being energized, it tends to move the vane C" to open the contacts in the local circuit -When an excess amount of mechanical connection is also such that should the vane l) have a reverse movement such movement will act to open the circuit on the coil C, and thus cause a reverse movement of the vane C to open the local circuit.

The two parts of the relay are identical in construction and operation and will respond to alternating currents of any frequency; but it will be apparent that unlesshoth parts are responsive to an alternating current the relay than the other.

scents will not be operated to close the local circuit. For, example, it ior any reason the vane D becomes inoperative then the vane C could not he'operated by an alternating current of the relay respond to the alternating signalingcurrent in the normal 'or usual operation of the system and not to the alternating propulsicn-curren't-to close the local circuit, 1'

provide means which act to impede the flow of the low-lrcquency alternating current in one of thetwo coils, so that-the alternatin signalingwurrentwill be stronger in one coi linother Words, there will be a preponderance of the alternating signaling-v current in one of the coils. .These means may he independent of the other parts of the relay, or they may be included in the con struction of the relay itself, or one of the two coils may he made to oilcr more impedance than the other. I

In the drawings I have shown the two coils in multiple circuit with the track-rails. In

the circuit of the coil C, l have included a noninductive ohmic resistance R, and in the circuit of the coil D, I have included an inductive resistance .i ll. The resistance 0 it may he dispensed with, it desired. As is well known, an inductive resistance impedes the ilow of an alternating current by its reactance, which varies in direct proportion to the frequencies. resistance l R will to a large extent impede the flow of the alternating signaling-fitment in the coil ll, and consequently there will be Therefore the inductive but a sli ht torque of the vane D, due to.

the signaling-current. However, this slight movement is availed of to close the circuit through the coil C.

The circuit for the coil D may be traced as follows: From one track-rail it is wire 1, inductive resistance I it, wire 2, coil .l), and wire 3 to other track-rail. The circuit for the coil C is wire 1, ohmic resistance 0 ll.

wire 4, coil C, wire 5, vane (.7, rod 1, and :vane l) and wire (5 toothcr traclm'ml. '1 bus -it will he soon that the circuit 01 the coil (3 is closed only when the vane D has moved the mechanical connection sullicicntly to engage the vane C. 1

In the usual operation of the railway and signaling system the pro'pulsion-currcnt will flow along the track-rails in its return to the generator and will not flow to any extent in any multiple circuits. For example, the leads from the relays and translorn'xers, owing to the rails oil'ering a path of least resistance, and the alternating.signaling-current will flow through the coils C and .D to

produce movements oi l;heir vanes C l), and as. more of the signaling-current Wlll. low through the coil 0 than the coil I), owing to IIO =' vane D has been moved sufficiently to engage the vane C.

Fig. illustrates the position of the parts oi relay when no car or train is in a block-sec- 7 tion. Fi 2 illustrates the position of the parts of t e relay when a car or train is in a block-section and the alternating signalingcurrent from the t ansformer is short-circuited ,from the coils C and D. These two fig ures illustrate what may be termed the normal or usual operation of the system.

Fig. 3 illustrates what may be termed an unusual condition-to wit, a break or other unusual resistance in one of the trackrails at thepoint X such as to cause adifl'erenceof potential of the power current to exist hetween the track-rails of the block-section. "With this difference of potential existing the propulsion-current would find a path through both the coils C andD but as themducti've resistance I R will offer less opposition to the flow of low frequency than high-frequency current, while the action of non-inductive resistance R is unaffected by frequency, re'la tiveiymore current will flow in the .to open the local circuit.

circuit of the coil D, and consequently there will been stronger pull on the vane D, which acting through the mechanical conne ctio n will cause a movement of the vane C In other words, in the event of the unusual condition illustrated in Fig. 3 there will be a preponderance vof I coils C and D the same operation would occur quency current must of the low-frequency current in the coil D. Also, in the case of'l i 2, should there be any difference in potential of power-current in the rails of a block-section occupied by a train (see 2) and should such difference potential cause a current to flow in the as hereinbefore stated. Thus it will be seen that in the normal or usual operation of the railway and signaling system the relay will operate in the usual way; but should some unusual condition in the track arise which might cause the propulsion-mirrorit to flow the relay would be operated (if at all) to open the local circuit rather than close it,

and thus indicate the dangerous condition. Also should the vane I) become inoperative lor any reason the local circuit Wlll not be closed and the signal indicate the dangerous condition, inasmuch as the circuit for the coil C is carried through the mechanical connection between the two vanes. Thus it will be seen that an advantage is obtained in having two vanes and a mechanical connection between the two for the reason that the vane and coil affected or o )eratedby the low-frehe in operable condition to close the circuit through the oil C If, therefore, the vane D is not moved upward for any reason, the. coil C is ineffective to move the vane C to close the local circuit; but if the vane Dis moved upward by an excessive amount of low-frequency current it causes the vane C to move to open the local circuit. Thus it will be seen that under no conditions will the low-frequency current operate the relayto close the local circuit.

What I claim as my invention is- 1. The combination with an electric rail way the trackway of which is used for the return of an alternating propulsion-current and is divided to form block-sections, of a signaling system therefor, said signaling systom-comprising. a railway-signal-for each block-section, and a trac:

block-section for controlling the railway-sigsource of alternating current of hlgher frequency than the propulsion-current, and a relay having two coils which when energized by a preponderance of the signaling-current will close a local circuit for the railway-signal and when energized by a preponderance of the propulsion-current will open the .local circuit.

2. The combination with an electric railway the trackway of which is used for the return of an alternating pro ulsion-curr'ent and is divided to form bloc r-sections, of a signaling system therefor, said signaling system comprising a railwa*-signal for -each block-section, 'and a tracer-circuit for each block-section for controlling the railwaysignal, and each track-circuit comprising a source of alternating current of higher frequency than the propulsion-current, and a relay having two coils, a movable element for each core, and a mechanical connection between the tw o coils,whereby wheh both coils are energized by the alternating signaling-currelay will operate to close a local circuit for a railway-signal and when both coils are ener gizcd by tho alternating propulsion-current and one by a preponderance thereof will opcrate the relay to open the local circuit.

3. The combination with an electric rail' way the trackway of which is used for the return of an alternating propulsion-current and is divided to form block-sections, of a IIO signaling system therefor, said signaling sys-..

tom comprising a railway-signal for eachv block-section, a track-circuitfor each blocksection for controlling the railway-signal and each track-circuit comprising a source of alternating current of higher frequency than the propulsion-current, and a relay having two coils arranged in multiple circuit with the track-rails and one of said circuits having more reactan'ce than the other, whereby when one of the coils is energized by a preponde-rance of the alternating signaling-current the relay will operate to close a circuit on the railway-signal -and when the other seem s coil is energized by a preponderance of the alternating propulsion-current the relay'will operate to open the circuit of the railway- .signal. I

- 4. In combination with a signaling system controlling contacts by its movements in response to the absence or presence in its coil ofa high-frequency alternating current, and

the second of said vanes mechanically connected with the first vane and controlling the circuit of the coil for the first vane.

5. The combination with conductors havlug-impressed thereon an alternating current therefor, said signaling system compris ngia' railway-signal for each block-section and a v of high frequency and an alternating current of low fre uency, of a relay having two coils both of w ich are connected with said con;

duetors in multiple circuit, means in-the circuit of one coil for selecting between the two currents, avane for each coil, one of which 1n one of its-movements closes the circuit through the coil of the first vane'and causes a movement of the first vane when the coil of the second vane is energized by a pre ponderance'of the low-frequency current.

6. The. combination with an electric rail-- way the trackway of which is used to conduct alternating propulsion-current and is divided to form'bloek-sections, of a signaling system track circuit for each block section, and

each track-circuit comprising a sourcepof alternating current of higher frequency than the propulsion-current and a relay which responds to the high-frequency current to close a local circuit for the railway-signal, and said relay comprising means which when 40 energized by the propulsion-current will not close the local circuit.

7. In combination with a signaling system for railways, relays for controlling the signals thereof, each relay comprising two coils, 4.5 means movable in response to the action of both coils for closing a circuit under the in fluence of current of 7 one frequency, and means responsive to changes in frequency for causing one of said coils to preponderate o to open the circuit under the, influence of current of a lowerfieque'nc y. i u

8. in conrbfiation with a signaling system iorrailways, relays'for controlling the signals thereof, each relay comprising two coils, means actuated by both coils to control a circuit, and means responsive to changes in frequency permitting said coils to cooperate and close the said circuit when energized by current of one frequencybut causing one coil to operate to open the circuit when energized by a preponderance of current of a lower frequency. I V

In testimony whereof I have signed my" J. S. HOBSON, W. L. MCDANIEL.

name to this specification in the presence of 

